Presence of thrombosis-inducing activity in plasma from patients with lung cancer

Thrombosis-inducing activity (TIA) was detected in the peripheral blood of some patients with advanced lung cancer. When plasma from the patients was given intravenously to mice or to guinea pigs, the animals became immobile within 2 min and died at 3 to 30 min after the injection. Multiple thrombosis was found in the lungs and was considered to be the cause of the death. Thrombosis was not formed and the mice survived when heparin was given intravenously 5 min before the injection of the plasma. This TIA was present in plasma from 13 of 42 patients with lung cancer. On the contrary, only two of 32 with chronic lung diseases and two of 31 healthy control subjects had this activity in the plasma. The coagulation system in the 13 patients was considered to be chronically activated, as revealed by elevation of plasma fibrinogen levels, fibrin degradation product levels, and/or peripheral platelet counts. The TIA shared characteristics with tissue factor in that it was heat labile, nondialyzable through a dialysis membrane with a 10,000 molecular weight exclusion limit, sensitive to phospholipase C treatment, precipitated by 50% ammonium sulfate, and bound to concanavalin-A Sepharose.